Consider the design task of specifying components for a positioning system. The "short" positioning requirement is to move an aluminum disk 5 degrees beginning and ending at rest, i.e. zero velocity....

Consider the design task of specifying components for a positioning system. The "short" positioning requirement is to move an aluminum disk 5 degrees beginning and ending at rest, i.e. zero velocity. The disk has inertia of .01 kg-m2 (approximately 1/2 inch thick, 9 no brake. The motor will have to both accelerate and decelerate the disk) a. Using an RBE 1803 motor (any winding) and assuming that the gears have no inertia, select a gear ratio. motor winding and motor operation conditions which will minimize short" positioning time. (You may assume the task is repeated continuously.) b. How much quicker can the "short" positioning task be accomplished with a longer motor, RBE 1804. and with a larger diameter motor, RBE 2101? Both deliver approximately 20% more torque. If a large load mass is driven through a ball-bearing screw which is directly coupled to a motor, what screw lead results in the greatest load acceleration? Your answer XCr. will depend on the allowable motor torque. the motor inertia and the load mass. Notes: 1. This problem is closely related to the two problems 3 and 4 in this homework assignment 2. A ball-bearing screw, more commonly referred to simply as a ball screw, is pictured in Figure 10.9 in Juvinall and Marshek (J&M). 3. Screw lead is defined in J&M Figure 10.1 4. Ball screw friction is often low enough that it can be neglected S. Ball screw inertia may become important, particularly if the screw is long. You may neglect screw inertia in the present case